


Fire on Fire

by 343EnderSpark, Neonbat



Category: Captain America (Movies), Iron Man (Movies), Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Abortion Contemplation, Anal Fingering, Anal Sex, Angst and Fluff and Smut, Anxiety, Anxiety Attacks, Aquaphilia, Avengers: Infinity War Part 1 (Movie) Compliant, Avoidance of any feminine terms for genitalia, Begging, Biting, Body Dysphoria, Bondage, Breathplay, Bucky Barnes's Metal Arm, Chastity Device, Cheating, Choking, Cock Rings, Cock Warming, Coming In Pants, Consensual Somnophilia, Crossdressing, Crying, Dirty Talk, Discussion of Abortion, Double Penetration, Dubious Consent, Dysphoria, Exhibitionism, Face-Sitting, Fingerfucking, First half is Stony, Food, Food Play, Food Sex, Frottage, Hate Sex, Intercrural Sex, Lactation, Lazy Sex, Light Bondage, Lingerie, M/M, Manhandling, Marks, Metal Arm Kink, Mpreg, Multi, Multiple Orgasms, Not Avengers: Endgame (Movie) Compliant, Oral Sex, Orgasm Control, Orgasm Delay/Denial, Orgasm Denial, Overstimulation, POV Alternating, POV Third Person Omniscient, Panic Attacks, Polyamory, Polyamory Negotiations, Pre-Threesome, Pregnant Sex, Rimming, Risk Aware Consensual Kink, Rough Sex, Sensation Play, Sensory Deprivation, Sensual Play, Sex Toys, Shameless Smut, Shower Sex, Sleepy Sex, Smut that developed feelings, Smut that developed plot, Somnophilia, Squirting, Switch Bucky Barnes, Switch Steve Rogers, Switch Tony Stark, Teasing, Temperature Play, Threesome, Threesome - M/M/M, Trans Male Character, Trans Tony Stark, Unsafe Sex, Vaginal Fingering, Vaginal Fisting, Vaginal Sex, Wall Sex, eventual stuckony, super strength
Language: English
Status: In-Progress
Published: 2020-03-11
Updated: 2020-03-11
Packaged: 2021-02-28 18:55:22
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,624
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23042101
Author URL: https://archiveofourown.org/users/343EnderSpark/pseuds/343EnderSpark, https://archiveofourown.org/users/Neonbat/pseuds/Neonbat
Summary: Steve snapped. It was just one time. Until it wasn’t.
Relationships: James "Bucky" Barnes/Steve Rogers, James "Bucky" Barnes/Steve Rogers/Tony Stark, James "Bucky" Barnes/Tony Stark, Steve Rogers/Tony Stark
Comments: 4
Kudos: 97





	Fire on Fire

**Author's Note:**

> About 90% of this fic is written, but we hit a bit of a 'life got busy and now we need motivation to finish' bump. Also majority was written before Endgame was out so the way things go later is inspired by the comic, not the movie, though most of that is background. This fic started out as a one off scene that we decided to keep working on and then the plot and feelings really took hold. Nearly every chapter but two has smut, so enjoy!

Tony hated himself for the first few minutes after he saw Steve's face. There was a part of him, the better part, that was glad his old friend was alive, but his darker side resented that Steve hadn't dissolved into dust instead of Peter. It was a horrible thought, one that made him feel even scummier inside, but he felt it all the same. 

Staring across the table at 'Captain America', Tony felt past hate burn in his gut. The last time he'd seen Steve, he'd been walking away with his parent's murderer, leaving him to the frigid wasteland. Yeah, he had a tracking device on him and he'd been picked up before frostbite set in, but the principle of it Tony couldn't forgive. 

They’d spent the last five minutes just glaring at each other, neither refusing to budge. Then something in Steve cracked, an emotion he’d pushed aside back in Siberia. That was when he rushed forward and pulled Tony to him, reaffirming that the man standing in front of him was real. 

The last few years had been a wild mess, having to come to terms with so many aspects of his identity. Steve was no longer Captain America. The Accords had seen to that. He had no true home, instead working mostly with T’challa to help him as he opened the borders to Wakanda. His whole life he had struggled with his sexuality. Meeting Tony and seeing how he held himself on display for all the world to see had left him aching to be comfortable in his own skin. Of course, it was seeing Bucky alive in front of him that made him realize he could not deny the truth any longer. He had been willing to throw everything away to be with the man he had been in love with since they were children. So he did. 

Then Thanos took Bucky and so many of the other people he cared about. Now, all he had left was his name and what he believed in. 

And Tony, though it was something tenuous at best. 

Steve slammed Tony against the wall, pressing himself into the smaller man wrapped around him. He kissed him, hoping to bruise him with his lips. 

This hadn’t been his intention. If he’d had his way, he would have avoided Tony like the plague. His emotions were too raw after the last few days, but Natasha had forced them into Tony’s office, telling them they had to work shit out if anything was going to be done. 

It quickly escalated from there. He didn’t speak, no words felt right. Instead he held Tony’s face to his, kissing him until neither of them could breathe, grinding against him through his pants, wanting some grounding friction in his unhinged desperation.

Steve was devouring Tony like it was his last lifeline on earth and-- _goddammit_. 

Tony's hands raked through Steve's good-ol-boy hair, scraping his scalp as he pushed his smaller body against Steve's mass. He felt like a doll against a man like Steve, nothing without his suit, but dammit, he wouldn't take this from Steve again. He wanted the man to feel the depths of his hatred, the searing burn of the bile inside. 

When they parted to breathe, Tony dove a hand down, grasping at Steve's belt buckle and unlatching it with a rough hand. It didn't matter how aggressive he was, he knew Steve of all people could take it and more. There was nothing Tony Stark, nor Iron Man, could do to hurt the perfect soldier against him. 

He bit Steve's lower lip when his hand snaked down the front of his pants, grasping over Steve's length. Of course the serum hadn't skimped here either. Figures.

Steve let out a growl as Tony bit him and wrapped his hand around his cock. Glaring at him before bringing a hand up, he turned Tony’s face away from him, unable to look at the anger in his eyes. It exposed the expanse of his neck and he latched his mouth there, biting enough to bruise but not break skin. 

Tony felt like he was being consumed. Steve was always a brickhouse and then some, but pushed against a wall like this, he had never felt more certain of his own fragility in his life. Yes, he could have called all his suits to him in a nanosecond and punched the perfect off of Steve's face, especially since he'd made some _upgrades_ after their last fight, but... 

That was exactly what this was about wasn’t it? 

Despite the power in which Steve handled him, Tony already felt himself soaking his eighty-dollar designer boxers from the rough manhandling as if he wasn't a grown-ass man in his forties. 

Steve backed away from the wall, pulling Tony off of him and roughly bending him over the desk in the middle of the room. He spread Tony’s feet apart and ripped the pants as he pulled them down, exposing Tony’s slick core. This had once been a dream of his, but back then it had been in such a different context, one where he would worship Tony, let him know he cared. But here in this moment, he just needed. What exactly, he didn’t know. 

Tony grunted as Steve unceremoniously changed positions and made him sprawl against his own desk, bent over like a whore in the back of church. Maybe later he'd cuss Steve out for ruining his five-hundred dollar pants and designer boxers, but right now the animal act of aggression out of mister goody-two-shoes was possibly the hottest thing Tony had experienced in his life, and a moan built itself on his tongue despite his frustrations. 

It was the first time Steve had ever gotten a good look at him. At first, Tony wasn't even sure Steve had understood what 'transgender' had meant all those years ago. There had seemed to be a cognitive dissonance between what Steve had imagined Tony being born as, and the cocky, square-chested man he was used to seeing every day. Imagining a ripe honeypot on a whiskey-drinking hardass like Tony Stark was more than most brains were equipped to handle. 

The strong, broad hand of America spread against his back, pinning him down, and Tony’s breath stuttered. Feeling Steve line himself up was dizzying. Tony had experimented with a _lot_ of people and toys in his years, but Steve was something else… Steve was goddamn Adonis and the perfect all-american good boy had a dick as thick as a baseball bat and Tony was pretty sure this might kill him but — 

Tony’s mental spiral was abruptly cut off as Steve buried himself to the hilt in one smooth stroke, and his eyes fluttered as his vision exploded in a burst of white. He clenched up around Steve with a chest-deep groan, nails digging grooves into the polished hardwood. 

Full to the brim, and stretched wide, Tony couldn’t bite back the bile.”Th-that’s all you got, _Cap_?” He smirked, rolling his narrow hips in a slow grind and biting back the trembling pleasure-pain it shot up his spine while doing so. 

Steve hadn’t been with anyone in ages, he was sensitive. It took a moment for him to regain control. He had intended to wait until Bucky was better. His last session with Shuri had been just a few days before the snap. They had made plans; Steve had wanted it to be special. 

He fought the tears as Tony’s scathing voice brought him to the now. 

“Quiet.” His voice, low and dangerous, growled out before he bit hard at Tony’s shoulder blade. There was no way he could handle Tony’s venom right now. 

Tony swallowed a shout as Steve's teeth buried themselves into the meat of his shoulder blade. _Fuck,_ it had been a long, long time since someone was this rough with him. He could already feel an ache building in his hips and the fiery hot sting of a forming bruise permeating his shoulder. He had seen Steve go ham in the battle field, but he'd never suspected for a moment that golden-boy Captain America could be like _this_ in a million years. 

There was a sick satisfaction in seeing Steve break, one that made the acid rise higher and higher inside of him until he couldn't dwell on it anymore without bursting into flames. 

A deep moan escaped Steve as he began to thrust, dragging out almost completely before slamming back in. It was a slow but brutal pace. He knew he should pick up speed, finish this and get it over with, but his body and mind were two separate entities at the moment. 

His hand on Tony’s back slid up into his hair, gripping and pulling on it, lifting Tony from the table. His mouth found Tony’s neck where he began to bite, leaving marks as he went. 

Gritting his teeth, Tony tried to bite back the sharp groans that punched from him every time Steve's cock punched murder into his cervix, but he was failing. The hand threaded tight into his dark mane was his breaking point, and Tony moaned openly. Steve was all over him, a physical weight with teeth and still Tony wanted more. He wanted until he couldn't possibly go anymore. 

" _Come on_ , g-give it to me...'nless you wanna c- Ahh, _fuck_ , cut and run now too." He growled, clenching himself up around Steve to root him deep, legs beginning to quiver. 

Steve let out a strangled sound, a mix of anger and pleasure, as Tony tightened around him. His words dug deep, reminding him of the last time they had actually seen each other. 

The hand in Tony’s hair flew around to grab his chin, three fingers covering his mouth while Steve’s pinkie held his jaw closed. His other hand left Tony’s hip and splayed over his chest to support as he shifted them to stand upright. “What part- of quiet- did- you- not- fucking- understand?” He spoke through gritted teeth as he punctuated each word with shallow, hard thrusts. 

He dropped his head onto Tony’s shoulder, his breathing labored as he felt his balls begin to tighten. Tony was so damn tight around him. It was exquisite yet painful, and it filled that strange need in him that he didn’t quite have a name for. 

For a pulse-pounding second, Tony was sure Steve was going to choke him. He pointedly ignored the thread of disappointment that settled in him when Steve only held his jaw shut instead. There was a part of him, the sick and twisted part, that wanted to feel what it would be like to have Captain America's broad hand wrapped around his throat until his head was dizzy with it. 

Tony hissed through clenched teeth, pissed that Steve had pushed him so far and yet _still_ was holding back. The motherfucker-- even when having a breakdown Steve had to be so goddamn _perfect_. 

But fuck, did this angle make Tony want to collapse until he could feel his legs again. He was seconds away from an orgasm that would hit him like a mac-truck and Steve had better be right behind him. Tony arched deep to get _just_ the right angle to have Steve obliterating his g-spot with every standing thrust, and he gave up fighting it anymore. 

His hands snapped to the desk, grasping at it to push himself back over Steve's cock as he desperately chased the high of his peak that was approaching with every drive into him. He didn't relent for a moment on Steve, staying as tight and flexed as possible, forcing the ridge of Steve's cockhead back and forth over his spot until he was all but whimpering against Steve's hand. 

With Tony arched against him, Steve began to gasp, everything becoming so intense. The muscles in his arms spasmed a moment, nearly dropping Tony back onto the desk. His hand on Tony’s chin shifted down, wrapping around his throat, but Steve was too far gone to realize. The one on Tony’s chest dug his nails in to keep hold. 

His legs shook, but he refused to fall. He was too damn close. He could feel Tony pulsing around him, so close himself. The hand digging into Tony’s chest moved down until two fingers found Tony’s dick, rolling it between them. 

Tony could have sobbed for joy at Steve's hand locking around his throat if he wasn't so pissed it had taken him so long to get the hint. The strength in that grip made Tony's eyes roll up, satisfied that he was firmly unable to escape even if he wanted to. Was it messed up that he was getting off on something that had made him want to pummel Steve's face into the cement in Siberia? Completely, but he was too far gone to care. 

Then Steve's hand was on his cock and it was all over. He seized up on Steve's dick with a breathless gasp, and the next hard drive against his cervix had a flood of heat releasing. Rarely did anyone get him so riled and desperate he squirted, especially all over his own goddamn desk, but feeling Steve's solid force against him was more than he could take. It felt like every major body function went offline at the same time as red-hot pleasure that bordered on agony lit up every nerve ending from toe to scalp. He couldn't breathe, think, or move, and it was bliss. He was coming all over Captain America's cock after half the world had been dusted, and he didn't give a fuck anymore. 

The sensation around his dick as Tony came apart in his hands caused Steve’s hips to stutter a few more thrust before he erupted inside Tony. He groaned deep, losing himself to the feeling. Before he was even finished coming, his legs gave out and he fell backwards to the ground. It barely registered for him until his cock slipped out of the warmth, still slowly leaking a bit of come. His hands slid off of Tony, and he kept his eyes closed, focusing on breathing, and not thinking about what just happened. 

Tony barely caught himself on his desk, hands gripping the side as he slid down to the floor to take in rough, greedy breaths that rapidly cleared the fuzz that was threatening the corners of his vision. His whole body shook like a leaf, bruised, marked up, and pulse through the roof...but it was still the most alive he'd felt since-- 

Tony rested his forehead against the desk, willing his breath to calm before the pleasant burn turned into the tight constriction of panic. It was difficult to cling to the satisfaction of being used so thoroughly that he could barely remember his name with the storm of reality encroaching down on him again. The world outside their little bubble was closing in, and he didn't want to face it. Where he still didn't fully know who was alive or dead. Where people weren't cursing the Avenger's names for their failure. 

Looking down between his legs at the growing puddle of his own ejaculate and Steve's and a sharp, harsh sound akin to a chuckle huffed from his abused throat. The sound built into a rough laugh until he was forced to stay bowed against the hardwood to keep himself from slipping down fully onto the soaked floor. He knew that if he got down, there was no way in hell he'd have the strength to get up again. 

Steve brought a hand up to his face, putting pressure on his eyes to stem the tears from falling. This wasn’t him, or, well, it hadn’t been. He didn’t fucking know anymore. The man he loved was gone _again. Half the world_ was gone because he wasn’t strong enough. And now he wasn’t even strong enough to fight off some base desire. He still couldn’t believe he’d just fucked Tony. There was no rhyme or reason, it just happened. 

Steve ran his hand down his face as he heard the laugh from Tony. Turning his gaze on the man who was barely keeping himself from collapsing, he let out a sigh. Of course Tony would find the sheer ludicrousness of the situation humorous. 

He brought both hands back to his face, pressing the heel of his palms into his eyes and bit his tongue to try and stifle a laugh as it bubbled up. It failed miserably, and the laugh came out strained and watery. The tears finally escaped from him as well.

It was jarring to hear Steve echo his delirious laugh, but there were other notes in Steve's voice. Cap always wore his bleeding heart on his sleeve. Tony could already see his blue eyes weighted with tears in his mind's eye without turning around. The last thing he wanted was to let any of the razors in his stomach dull just because Steve looked like a kicked puppy when he was upset. If the avengers had just stayed together....if they hadn't been scattered to the wind, maybe...just maybe.

After a moment, Steve regained his composure enough to sit up, wiping at his face. He looked around for something to clean up with, but his gaze fell on Tony’s ripped pants and he cringed. They wouldn’t be salvageable enough for Tony to use. 

“We’re a fucking mess, aren’t we?” he said, forlornly, running a hand through his hair, shifting his eyes guiltily from Tony.

Tony’s laughter finally dried up and he sighed, knocking his forehead against the desk. "Guess we are if golden-boy is cussing now." His throat was raspy, and he would probably have to nurse a cup of coffee or two to get back to stasis, that was whenever he could get up again. His legs felt like jelly and he was pretty sure his hips might not ever work again. 

Swallowing, he turned to put his back to the desk. A weary sigh escaped him as he relaxed, content to sit in their mess while the world tried to right itself again. 

"Friday." 

"Yes Mr Stark?" 

"Two sets of clothes and a goddamn lozenge. Please." 

"Right away." 

Tony Stark was always prepared. Be it at the compound or his own wing, he wasn't going to leave out of here looking like-- looking like he had just gotten railed six ways til Sunday by Captain America. 

Steve stood after a moment, before the oppressive silence could drag on between them and spotted tissues on the desk. Making his way over, he stood a few feet away from Tony as he used the tissues to clean himself off as best he could. He gently shifted himself back into his pants, but couldn’t stop the hiss that slipped from him. It was impossible for him to know how Tony physically felt at that moment, though by his voice, he could tell that his throat was wrecked. 

He took a deep breath and grabbed the tissues before crouching and holding them out to Tony. 

“I’m sorry.” 

His words wouldn’t accomplish much. He had been close with Tony before...well before everything went belly up. It was a start though.

Tony brought his gaze up enough to look at the tissues, glaring weakly at the reminder that Steve had left him more fucked than Tony could ever hope of doing to Steve. Everything felt like it looped back to Siberia, over and over again. 

When he snatched the tissues from Steve's hand, the hard pull of the bite mark swelling on his shoulder caused him to wince. "For?" Sneering, he reached back to see if Steve had broken the skin. "For ripping my favorite pants, making me have to take Plan B like a college slut, or for _leaving me in the middle of goddamn Siberia in a broken suit_ , just so we're on the same page." He hissed through his teeth. 

He could have walked away from this and bullshitted to the others that everything was hunky-dory. That he and Cap could work together to tackle this clusterfuck of a world they'd been left with. But then Steve had to go being _Steve_ and apologize, sending the fire blooming right back in the hollow pit of Tony's stomach. 

Steve winced as Tony’s words hit all the nails on the coffin. They had a lot of issues to work through, but Siberia was going to be the big one, to nobody’s surprise. He couldn’t really blame him. They had been teetering on that will-they-won’t-they edge when Bucky had reappeared in DC. Tony had even helped with his resources to track down Bucky. Then everything went to hell with the Accords and the truth about Tony’s parents. He still had no idea how to fix any of it. 

“All of the above.” Steve said, sitting on the floor and crossing his legs. “We got played like a damn fiddle and I let everything spiral beyond my control.” He ran a hand through his hair. “I’m sorry I didn’t tell you about your parents when I found out, but one thing I will not apologize for is siding with Bucky.” Gritting his teeth, he prepared for Tony’s ire. 

If Tony had the energy or knew it would actually do anything, he would have hauled off and punched Steve then and there. Why did Steve have to be so relentlessly _Steve_? Even after all this, Captain bloody America was apologizing. Tony had almost been _relieved_ to see Steve break finally. To feel his anger and frustration channeled in a negative way. For once, it had made Steve seem like a normal human being, and not some.... 

Not someone that Tony had started to feel ashamed standing next to. Steve felt like a sun half the time and Tony was just trying not to get burned. Having Steve say fuck-all for the Winter Soldier had been the first time Tony had even realized there was anything behind that all american visage outside of what the government had made him. 

But then of course, things had gone to hell in a handbasket. 

"Yeah, well I guess it all doesn't matter much now, does it?" It was harsh even to his own ears, but undeniably true. No matter what side they had been on, both their decisions had led to nothing in the end. The world was still in chaos, and now Bucky was as much dust in the wind as anyone else taken by Thanos' mania. 

That wasn’t exactly what Steve had been expecting from Tony, but it still managed to make him bristle. The muscles in his jaw flexed as he worked on keeping himself from grinding his teeth. 

“It still matters. It’s just not what we should be arguing about right now.” Steve ran a hand over his face. “We shouldn’t be arguing at all. We need to figure out how to undo this mess.”

Tony sideyed Steve, quirking an eyebrow when his barb didn't garner the desired effect. Why he wanted it, why he continued to want it, Tony didn't know, but he _hated_ that Steve looked like he was starting to get his head on straight already when Tony felt as adrift as he had an hour ago. 

Steve glanced to the side as the door opened, revealing a small robot carrying the previous items Tony had asked for. Automatically he moved to stand between Tony and the door, offering some form of chance at decency. 

"Jesus," Tony rolled his eyes, getting to his feet with a small grunt. An involuntary shiver danced up his spine now that he was upright, the tell-tale repercussions of going bareback making itself known down his thighs. That...wasn't a sensation he'd felt in a while. Usually he didn't fuck like that much anymore, but he hadn't even second guessed it with Steve. Just another match-stick to the firepit in his gut. 

Any other time he might have teased Steve and his sense of propriety, but considering it was Steve's fault he needed a change of clothes to start with, Tony just shook his head as he took the neat bundle from the robot. He tossed the second bundle to Steve and made quick work of opening the package of medicated throat-candies to pop one on his tongue. Turning away, he disappeared into the small bathroom attached to his office.

Steve caught the bundle of clothing tossed to him. He looked down at his current clothing which had made it almost unscathed from only a few minutes ago. He hadn’t really thought about it when Tony had asked for two pairs of clothes, having been too in his own head. Still, it wouldn’t be wise for him to leave the room with the now-drying stain on the front of his pants. 

"And what do you suggest? Because last time I checked, we looked pretty fucked from all sides." Tony asked from the other room. Rarely did Tony ever admit defeat, but he was at a loss for what to do. They had given it their goddamn all, and no matter what Mysterious Cape-guy said, Tony didn't see a way to fix it. 

Steve set the clothes on the desk as he began to strip. Suggest? He really had no clue where to even begin. Already he had spent hours upon hours since the fight trying to formulate plans, but there was always something missing. He couldn’t figure out what though. 

“I don’t know.” He did his best to try and keep the sound of defeat from his voice, but he already knew he failed at that. “Last I checked, Bruce was still trying to take stock of who was alive and able to help. Unless we can figure out some way to locate the gauntlet or Thanos, we’re stuck.” They could not give up that easily. “I saw what the gauntlet is capable of. If we could get a hold of it, we could undo everything.” 

He finished getting dressed, pulling the t-shirt over his head. It was a little tight, but Tony did tend to undersize garments. 

There was the brief sound of running water as Tony cleaned himself up, wincing slightly at how tender things were in certain areas. Had the situation been different, Tony might have more than enjoyed doing what they did and more, but those felt like thoughts from what seemed a lifetime ago. Jesus, things had been different then. 

"Friday, put out an order for Plan B." He grumbled, briefly pressing over his lower abdomen. He'd never taken the time to get anything tied or taken out. It always seemed needless, and if he was honest about it, there was always a tiny part of himself that panicked at the idea. Did he want children? The question was always met with a nebulous no, but obviously it was shaky enough if he hadn't done anything about the internal plumbing yet. 

Shaking that particularly fruitless strain of thought away, Tony returned to the task at hand. "Let's get a list first, see what we can work with. I'll get relief efforts on the ground, we'll...fuck it, you win Cap, we're working off borders here. Pool all resources, let's get a plan going." Tony tried to sound like he usually did, the man with a plan, but right now, he just wanted to curl up in his room and die for a little while. Nothing, and no one, could undo the past week, and the idea of continuing on churned nausea in his gut. 

He dressed, tugging on his jeans and hoodie with rough hands. "Let's fix this clusterfuck or die trying." 

**Author's Note:**

> Lotsa thanks to [EmmettM2025](https://archiveofourown.org/users/EmmettM2025/pseuds/EmmettM2025) for helping with those big edits, [Narutaisho](https://archiveofourown.org/users/Narutaisho) for being another pair of beta eyes, and [thelonebamf](https://archiveofourown.org/users/thelonebamf/pseuds/thelonebamf/works) for letting me pester her as I often do.


End file.
